Light Bulb
First and foremost, check if the light bulb is switched on. If the lamp is on, this means that the heater is still supplied with electricity and that all other elements in the electrical circuit are good. At the same time, it is a sign that there is a problem with the heaters and they need to be replaced.
Check Installation
To make sure that the heater or heaters do not work properly, it is necessary to check the installation on the heater more carefully, and if it is in a good condition, then the heating element is definitely burned.
Element Malfunction
If the small light bulb does not work when the water heater is switched on and off, of course, the device does not heat the water, then it is very likely that there is a malfunction on some element of the electrical installation, and for determining it, you need a special device which is called a power meter. But if you do not have any experience with this, it is better to call a professional who will find out where the problem is.
Locating the problem with your electric water heater is a complex process and the process is far more secure if you hire a professional. The entire procedure consists of checking of each element and its contacts, and replace the faulty ones. This applies for the heaters and the thermostats as well. Of course, all of this is related to electrical faults and most commonly the problems with electric water heaters happen because of failure of the heater that is damaged due to sedimentation stones. Again, if you are not sure what the real problem is, make sure that you do not damage other parts of the device. Also, it is not recommended for inexperienced individuals to do this due to safety.